The present invention relates to an electrochemical battery cell having a housing that includes a container and a collector assembly for sealing the electrochemical battery cell.
Batteries used as power sources for electronic equipment can store large amounts of energy. Batteries can contain one or more electrochemical battery cells. Pressure inside the electrochemical battery cell can increase due to changes in internal temperature, an increase in internal volume of electrodes during discharge and gases generated during cell charging, in the case of rechargeable batteries, and discharge. Such electrochemical battery cells typically include a mechanism for releasing or discharging gas from the cell to limit the buildup of internal pressure.
Electrochemical battery cells can have an open-ended container and a collector assembly disposed at the open end of the container to close the electrochemical battery cell. The collector assembly can include a safety pressure release vent mechanism that releases excessive pressure.
Various collector assembly and pressure release vent designs have been used in electrochemical battery cells. For example, resealable pressure relief vents can be found in rechargeable aqueous electrolyte cells, such as nickel-cadmium and nickel-metal hydride cells. Primary (nonrechargeable) aqueous cells, such as alkaline zinc-manganese dioxide cells, have used collector assemblies with relatively large surface area plastic seals containing a weak section that can rupture when the internal pressure exceeds a predetermined limit. Primary and rechargeable nonaqueous electrolyte cells, such as cells with electrodes containing lithium metal and lithium intercalation materials, typically have collector assemblies with thin-walled plastic sealing members to minimize vapor transmission and pressure relief vents that are able to very quickly reduce internal pressure.
Examples of conventional collector assembly and pressure release vent designs can be found in: U.S. Pat. Nos. 4,963,446 (issued to Roels et al. Oct. 16, 1990), 5,015,542 (issued to Chaney, Jr. et al. May 14, 1991), U.S. Pat. Nos. 5,156,930 (issued to Daio et al. Oct. 20, 1992), 5,609,972 (issued to Kaschmitter et al. May 11, 1997), 5,677,076 (issued to Sato et al. Oct. 14, 1997), 5,741,606 (issued to Mayer et al. Apr. 21, 1998) and 5,766,790 (issued to Kameishi et al. Jun. 16, 1998). Each of these examples has a large collector assembly volume or dimensional constraints limiting the volume within the cell for active ingredients or a large number of components making the cell more costly and difficult to manufacture.